Purple fringing was a problem with A*135 on *istD, but it seals to be less on cmos sensors. It works great on K-5.
DagT Sendt fra min iPad > Den 16. okt. 2013 kl. 21:12 skrev "P.J. Alling" <[email protected]>: > > Purple fringing as in sensor bloom happens in high contrast areas, I suspect > that in some ways, some very good on film, older lenses are too good for > digital. They achieve apparent high sharpness by emphasizing contrast which > under many conditions exacerbates bloom. > >> On 10/16/2013 1:21 PM, Dario Bonazza wrote: >> Practical experience shows that the best old FF lenses are quite decent >> performers on APS-C sensors, sometimes comparable to good 'digital' lenses >> (at least up to 12-16 megapixels), except for a typical higher CA and purple >> fringing. That's because you get rid of the weaker part of their image >> field. Oh, and that only applies to focale lengths around 35mm or longer >> (most if not all older wide-angle lenses are much overperformed by current >> APS-C digital sensors). >> On the other hand, I still have to find a single 'analog' lens which is >> comparable to newer lens designs on FF sensors with a pixel count of 24 or >> 36 MP. >> Heck, even most FF digital designs cannot cope with the D800 sensor! Sure >> you can use whatever lens you like on a modern FF DSLR (provided you can fit >> and focus it), but don't expect to exploit their potential. >> >> Dario >> >> -----Messaggio originale----- From: J.C. O'Connell >> Sent: Wednesday, October 16, 2013 6:57 PM >> To: Pentax-Discuss Mail List >> Subject: Re: K3 problem using flash and AA >> >> My Reply : I disagree with regards to full frame. As long as the corner >> performance of the FF lenses >> matches 2/3 of the performance of the APSC lenses the overall system >> performance of FF will >> be equal to or greater than the Aps performance. Generally speaking, >> you dont need as high a >> performance FF lenses for better overall system performance than apsc. >> Its a larger format, it has >> more overall lines of resolution even if the absolute line pairs/mm is >> lower. >> >> >> Regard no AA filter, aliasing occurs when the incoming spatial >> frequencies are too fast >> for the sampling. With a high resolution sensor and cheaper lower >> resolution lenses, >> NO aliasing will likely occur. Aliasing is more likely to occur with >> super high spec ultra >> high resolution * or APO lenses, not average or poor ones. >> >> >> >>> On 10/16/2013 9:38 AM, Dario Bonazza wrote: >>> Darren Addy wrote: >>> >>> Cameras with no AA filter are going to separate the "men from the >>> boys" as far as lenses are concerned. It is going to make APO and Star >>> lenses almost mandatory. Either that or you are going to have to >>> "enjoy" a lot more time in post-processing. This problem is >>> exacerbated by a full frame sensor which uses the corners of the image >>> circle that are getting cropped out by an APS-C camera. In short, >>> those who want a full frame DSLR are either going to have to use their >>> best lenses with it, or procure some. >>> >>> My reply: >>> >>> I keep telling that to all those funky boys begging Pentax for a full >>> frame camera and counting on good lenses of the past they already own and >>> treasure. Once FF will be available, you'll have to buy a whole new lens >>> outfit based on new-generation lenses (provided they will be made >>> available) or be satisfied with so-so performance. >>> >>> That's well known by Canon and Nikon shooters, and mostly neglected among >>> dreaming Pentaxians. In brief, putting together a Pentax FF outfit won't >>> cost you less than switching to Canon or Nikon, the advantage being you >>> won't have to do that all at once. >>> >>> Dario > > > -- > A newspaper is a device for making the ignorant more ignorant, and the crazy, > crazier. > > - H.L.Mencken > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
